JPS60213049A - Package for semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To prevent an effect on a chip, and to improve the memory holding characteristics of the chip by dividing a molding resin for an ultraviolet erasing type EPROM resin mold package into two upper and lower sections with hollow inside. CONSTITUTION:With the ultraviolet erasing type EPROM resin mold package, a molding resin is divided into two upper and lower sections, and changed into a lower molding resin 11a, to which a lead frame 9 section is held, and an upper molding resin 11b, a hollow inside thereof coveres an EPROM chip 3 mounted onto the lead frame 9, bonding wires 4 for the chip, etc. without being directly brought into contact with these chip, bonding wires, etc. Since the upper molding resin 11b is not brought directly into contact with the EPROM chip 3, the infiltration of a contaminant having an effect on the memory holding characteristics of an EPROM can be prevented by resin components.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a semiconductor integrated circuit package, and more particularly to an ultraviolet erasable EFROM resin mold package.

[Prior art]

Typical UV-erasable EPROM chips are housed in a pan cage with a UV-transparent window so that written memory information can be erased using UV light.
For this package, usually due to the special feature of having a UV-transparent window.

A ceramic package is used, with a hollow space between the EPROM chip and a lid with a UV-transparent window. Figures 1 (B) and (C) show the general configuration of this general ultraviolet-erasable EF ROM panpackage.

0). That is, in these first figures) to ■), reference numeral 1 indicates a ceramic substrate having a lead bin 2;
3 is an EP mounted on the concave surface of this ceramic substrate 1.
ROM chip, 4 its bonding wire, 5 adhesive glass on the ceramic substrate 1, 6a a ceramic lid with a lid T provided with an ultraviolet ray transmitting window 8, and 6b a ceramic lid with an ultraviolet ray transmitting window 8. .

Another conventional example that has been attracting attention over the past few years is the ultraviolet erasable EFROM resin mold package. Figure 2 shows its general configuration.

In the case of the conventional configuration shown in FIG. 2, the EPROM chip 3, its bonding wires 4, and the lead frame 9 that mounts them are all sealed in a molding resin 10, and are in contact with the side surfaces of the memory cells and peripheral circuits of the EPROM chip. In this conventional configuration, since no ultraviolet light transmission window is formed and the written memory information cannot be erased, it is assumed that the memory information can be written only once. In other words, this conventional configuration is attracting attention as a substitute for the high cost of pancakes with ultraviolet-transmitting windows, and it is possible to write memory information only once.
For applications that are limited to once use, it has a cost advantage.

The long-term reliability characteristics of this type of ultraviolet-erasable E FROM, such as memory retention characteristics and moisture resistance, depend on the characteristics of the pansivation film on the surface of the EFROM chip, the material of the molding resin in contact with the film, and the molding process. It is known that this is affected by factors such as the degree of pressure of the molding resin on the litter, but this did not pose a particular problem when the EFROM chip was housed in a hollow package with an ultraviolet-transparent window. This conventional ultraviolet erasable EPROM resin mold package has a drawback in that the retention characteristics and writing characteristics are deteriorated.

[Summary of the invention]

In view of the above-mentioned drawbacks of the conventional technology, the present invention provides an ultraviolet-erasable EPROM resin mold pancage.
The side surfaces of the memory cells and peripheral circuits of the Mchimp are arranged in a hollow interior to prevent the EFROM chip from coming into direct contact with molding resin or the like.

[Embodiments of the invention]

Hereinafter, one embodiment of the ultraviolet erasable EFROM resin mold package according to the present invention will be described in detail with reference to FIG.

This embodiment in FIG. 3 is shown in response to the conventional example in FIG. 2, and the same reference numerals indicate the same or corresponding parts in each figure.
．． The bonding wire 4 and the board frame 9 on which they are mounted are all molded with resin.
A lower mold resin 11a that holds the lead frame 90 portion and an E P mounted on the lead frame 9.
ROM Chimp 3. The upper mold resin 11b covers the bonding wire 4 and the like in a hollow interior without directly touching them.

Therefore, in the case of this embodiment configuration, the upper mold resin 1
1b does not directly touch the EPROM chip 3, the resin component can prevent contaminants from penetrating into the EPROM chip 3 that would affect the memory retention characteristics of the EPROM. This eliminates the pressure caused by foreign matter on the chip surface, pinholes in the pansivation film, and defects in the chip, which were one of the causes of defects in the conventional EPROM template contact mold [fat bankage]. It is possible to prevent defects such as crushing of memory cells and peripheral circuits due to unevenness on the surface, contaminants caused by mold resin entering through defects due to pansivation, etc. Furthermore, it is possible to prevent bonding wires from being compressed by mold resin. Therefore, it is possible to prevent wire breakage.

〔Effect of the invention〕

As described in detail above, according to this invention, the ultraviolet erasing type l
In PROM resin mold package, EFROM
The mold resin was divided into upper and lower halves so that the side surfaces of the chip's memory cells and peripheral circuits were arranged inside the hollow, and the mold resin was prevented from directly touching the EPROM cheer 7', so that the gPROM chip could be burned. This has the advantage that the influence can be reliably prevented, thereby improving the memory retention characteristics and write characteristics of the EFROM chip.

[Brief explanation of drawings]

Figures 1 (to), (B), (C) and 0) are general ultraviolet surface diagrams, and Figure 2 is a conventional ultraviolet erasing type E.
FIG. 3 is a cross-sectional view showing the general structure of a PROM resin mold package, and FIG. 3 is a cross-sectional view showing the general structure of an ultraviolet erasable EFROM resin mold package according to an embodiment of the present invention. 3...EPROM chip, 4 fists 0 bonding wire, 9 fists 11-1 node frame, 11a. 11b...Lower and upper mold resin. Representative Person Person Iwa 坩° Male @ 1 Figure

Claims (1)

[Claims] In an ultraviolet-erasable gFROM resin mold package, the mold resin is placed vertically two times so that the sides of the memory cells and peripheral circuits of the EPROM chip are placed inside the hollow.
A semiconductor integrated circuit pancase characterized in that the mold resin is divided to prevent direct contact with an EPROM chip.